// TableBuilder

// Takes the function passed to the "createTable" or "table/editTable"
// functions and calls it with the "TableBuilder" as both the context and
// the first argument. Inside this function we can specify what happens to the
// method, pushing everything we want to do onto the "allStatements" array,
// which is then compiled into sql.
// ------
const each = require('lodash/each');
const extend = require('lodash/extend');
const toArray = require('lodash/toArray');
const helpers = require('../util/helpers');
const { isString, isFunction, isObject } = require('../util/is');

class TableBuilder {
  constructor(client, method, tableName, tableNameLike, fn) {
    this.client = client;
    this._fn = fn;
    this._method = method;
    this._schemaName = undefined;
    this._tableName = tableName;
    this._tableNameLike = tableNameLike;
    this._statements = [];
    this._single = {};

    if (!tableNameLike && !isFunction(this._fn)) {
      throw new TypeError(
        'A callback function must be supplied to calls against `.createTable` ' +
          'and `.table`'
      );
    }
  }

  setSchema(schemaName) {
    this._schemaName = schemaName;
  }

  // Convert the current tableBuilder object "toSQL"
  // giving us additional methods if we're altering
  // rather than creating the table.
  toSQL() {
    if (this._method === 'alter') {
      extend(this, AlterMethods);
    }
    // With 'create table ... like' callback function is useless.
    if (this._fn) {
      this._fn.call(this, this);
    }
    return this.client.tableCompiler(this).toSQL();
  }

  // The "timestamps" call is really just sets the `created_at` and `updated_at` columns.

  timestamps(useTimestamps, defaultToNow, useCamelCase) {
    if (isObject(useTimestamps)) {
      ({ useTimestamps, defaultToNow, useCamelCase } = useTimestamps);
    }
    const method = useTimestamps === true ? 'timestamp' : 'datetime';
    const createdAt = this[method](useCamelCase ? 'createdAt' : 'created_at');
    const updatedAt = this[method](useCamelCase ? 'updatedAt' : 'updated_at');

    if (defaultToNow === true) {
      const now = this.client.raw('CURRENT_TIMESTAMP');
      createdAt.notNullable().defaultTo(now);
      updatedAt.notNullable().defaultTo(now);
    }
  }

  // Set the comment value for a table, they're only allowed to be called
  // once per table.
  comment(value) {
    if (typeof value !== 'string') {
      throw new TypeError('Table comment must be string');
    }
    this._single.comment = value;
  }

  // Set a foreign key on the table, calling
  // `table.foreign('column_name').references('column').on('table').onDelete()...
  // Also called from the ColumnBuilder context when chaining.
  foreign(column, keyName) {
    const foreignData = { column: column, keyName: keyName };
    this._statements.push({
      grouping: 'alterTable',
      method: 'foreign',
      args: [foreignData],
    });
    let returnObj = {
      references(tableColumn) {
        let pieces;
        if (isString(tableColumn)) {
          pieces = tableColumn.split('.');
        }
        if (!pieces || pieces.length === 1) {
          foreignData.references = pieces ? pieces[0] : tableColumn;
          return {
            on(tableName) {
              if (typeof tableName !== 'string') {
                throw new TypeError(
                  `Expected tableName to be a string, got: ${typeof tableName}`
                );
              }
              foreignData.inTable = tableName;
              return returnObj;
            },
            inTable() {
              return this.on.apply(this, arguments);
            },
          };
        }
        foreignData.inTable = pieces[0];
        foreignData.references = pieces[1];
        return returnObj;
      },
      withKeyName(keyName) {
        foreignData.keyName = keyName;
        return returnObj;
      },
      onUpdate(statement) {
        foreignData.onUpdate = statement;
        return returnObj;
      },
      onDelete(statement) {
        foreignData.onDelete = statement;
        return returnObj;
      },
      deferrable: (type) => {
        const unSupported = [
          'mysql',
          'mssql',
          'redshift',
          'mysql2',
          'oracledb',
        ];
        if (unSupported.indexOf(this.client.dialect) !== -1) {
          throw new Error(`${this.client.dialect} does not support deferrable`);
        }
        foreignData.deferrable = type;
        return returnObj;
      },
      _columnBuilder(builder) {
        extend(builder, returnObj);
        returnObj = builder;
        return builder;
      },
    };
    return returnObj;
  }

  check(checkPredicate, bindings, constraintName) {
    this._statements.push({
      grouping: 'checks',
      args: [checkPredicate, bindings, constraintName],
    });
    return this;
  }
}

[
  // Each of the index methods can be called individually, with the
  // column name to be used, e.g. table.unique('column').
  'index',
  'primary',
  'unique',

  // Key specific
  'dropPrimary',
  'dropUnique',
  'dropIndex',
  'dropForeign',
].forEach((method) => {
  TableBuilder.prototype[method] = function () {
    this._statements.push({
      grouping: 'alterTable',
      method,
      args: toArray(arguments),
    });
    return this;
  };
});

// Warn for dialect-specific table methods, since that's the
// only time these are supported.
const specialMethods = {
  mysql: ['engine', 'charset', 'collate'],
  postgresql: ['inherits'],
};
each(specialMethods, function (methods, dialect) {
  methods.forEach(function (method) {
    TableBuilder.prototype[method] = function (value) {
      if (this.client.dialect !== dialect) {
        throw new Error(
          `Knex only supports ${method} statement with ${dialect}.`
        );
      }
      if (this._method === 'alter') {
        throw new Error(
          `Knex does not support altering the ${method} outside of create ` +
            `table, please use knex.raw statement.`
        );
      }
      this._single[method] = value;
    };
  });
});

helpers.addQueryContext(TableBuilder);

// Each of the column types that we can add, we create a new ColumnBuilder
// instance and push it onto the statements array.
const columnTypes = [
  // Numeric
  'tinyint',
  'smallint',
  'mediumint',
  'int',
  'bigint',
  'decimal',
  'float',
  'double',
  'real',
  'bit',
  'boolean',
  'serial',

  // Date / Time
  'date',
  'datetime',
  'timestamp',
  'time',
  'year',

  // Geometry
  'geometry',
  'geography',
  'point',

  // String
  'char',
  'varchar',
  'tinytext',
  'tinyText',
  'text',
  'mediumtext',
  'mediumText',
  'longtext',
  'longText',
  'binary',
  'varbinary',
  'tinyblob',
  'tinyBlob',
  'mediumblob',
  'mediumBlob',
  'blob',
  'longblob',
  'longBlob',
  'enum',
  'set',

  // Increments, Aliases, and Additional
  'bool',
  'dateTime',
  'increments',
  'bigincrements',
  'bigIncrements',
  'integer',
  'biginteger',
  'bigInteger',
  'string',
  'json',
  'jsonb',
  'uuid',
  'enu',
  'specificType',
];

// For each of the column methods, create a new "ColumnBuilder" interface,
// push it onto the "allStatements" stack, and then return the interface,
// with which we can add indexes, etc.
columnTypes.forEach((type) => {
  TableBuilder.prototype[type] = function () {
    const args = toArray(arguments);
    const builder = this.client.columnBuilder(this, type, args);
    this._statements.push({
      grouping: 'columns',
      builder,
    });
    return builder;
  };
});

const AlterMethods = {
  // Renames the current column `from` the current
  // TODO: this.column(from).rename(to)
  renameColumn(from, to) {
    this._statements.push({
      grouping: 'alterTable',
      method: 'renameColumn',
      args: [from, to],
    });
    return this;
  },

  dropTimestamps() {
    // arguments[0] = useCamelCase
    return this.dropColumns(
      arguments[0] === true
        ? ['createdAt', 'updatedAt']
        : ['created_at', 'updated_at']
    );
  },

  setNullable(column) {
    this._statements.push({
      grouping: 'alterTable',
      method: 'setNullable',
      args: [column],
    });

    return this;
  },

  check(checkPredicate, bindings, constraintName) {
    this._statements.push({
      grouping: 'alterTable',
      method: 'check',
      args: [checkPredicate, bindings, constraintName],
    });
  },

  dropChecks() {
    this._statements.push({
      grouping: 'alterTable',
      method: 'dropChecks',
      args: toArray(arguments),
    });
  },

  dropNullable(column) {
    this._statements.push({
      grouping: 'alterTable',
      method: 'dropNullable',
      args: [column],
    });

    return this;
  },

  // TODO: changeType
};

// Drop a column from the current table.
// TODO: Enable this.column(columnName).drop();
AlterMethods.dropColumn = AlterMethods.dropColumns = function () {
  this._statements.push({
    grouping: 'alterTable',
    method: 'dropColumn',
    args: toArray(arguments),
  });
  return this;
};

module.exports = TableBuilder;
